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Thermosetting plastics
Thermosetting plastics, also known as thermosets, are a type of polymer that undergoes a chemical reaction during curing and becomes permanently hardened.
Unlike thermoplastics, once thermosetting plastics are set, they cannot be melted or reshaped through heating. This irreversible curing process is typically induced by heat, pressure, or a combination of both. Here are some
Thermosetting plastics are widely used in industries where dimensional stability, high heat resistance, and superior mechanical properties are required. They are commonly found in electrical and electronic components, automotive parts, aerospace applications, coatings, adhesives, and construction materials. The irreversible curing process of thermosetting plastics provides them with excellent strength and stability, making them suitable for various demanding applications.
Examples of thermosetting plastics include:
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Epoxy Resin: Epoxy resin is a versatile thermosetting plastic known for its excellent adhesive properties, chemical resistance, and high strength. It is commonly used in coatings, adhesives, composites, and electrical applications.
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Phenolic Resin: Phenolic resin is a thermosetting plastic derived from phenol and formaldehyde. It has high heat resistance, flame retardancy, and good electrical insulating properties. Phenolic resin is used in molded products, electrical components, laminates, and friction materials.
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Melamine Formaldehyde (MF): Melamine formaldehyde is a thermosetting plastic known for its hardness, durability, and resistance to heat, chemicals, and moisture. It is widely used in the production of dinnerware, countertops, laminates, and decorative surfaces.
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Urea Formaldehyde (UF): Urea formaldehyde is a thermosetting plastic derived from urea and formaldehyde. It has good dimensional stability, electrical insulation properties, and resistance to water and chemicals. UF resin is used in adhesives, particleboard, plywood, and molding compounds.
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Polyester Resin: Polyester resin is a thermosetting plastic that is commonly used in fiberglass reinforced plastics (FRP) applications. It has good mechanical properties, chemical resistance, and dimensional stability. Polyester resin is used in boat building, automotive parts, pipes, and construction materials.
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Polyurethane (PU): Polyurethane is a versatile thermosetting plastic that exhibits excellent flexibility, durability, and chemical resistance. It is used in a wide range of applications, including foams, coatings, adhesives, sealants, and elastomers.
Properties of thermosetting plastics
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- They permanently harden on heating above a certain temperature.
- They undergoes chemical changes during manufacture.
- They cannot be melted and reshaped.
- They have little potential for recycling.